1. Field
This relates to substrate processing systems, and more particularly, to monitoring systems used in substrate processing systems to facilitate the transfer of substrates.
2. Background
Flat panel displays may include liquid crystal displays, plasma display panels, organic light emitting diodes, and other such devices. These flat panel displays may be manufactured using a vacuum processing apparatus that includes a process chamber, a load lock chamber and a transfer chamber.
The process chamber processes the surface of a substrate by, for example, conducting an etching process using plasma, thermal energy, and the like in a vacuum. The load lock chamber receives an unprocessed substrate from the outside, and discharges a processed substrate to the outside while alternating between an atmospheric condition and a vacuum condition. The transfer chamber may serve as an intermediate holding place when introducing and discharging substrates into and out of the process chamber. To this end, the transfer chamber may be positioned between the process chamber and the load lock chamber. Proper sequencing and transfer of substrates into and out of the process chamber is important in ensuring proper processing of the substrates and preventing damage to the substrates during transfer.